Problem: $\dfrac{6}{5} - \dfrac{7}{6} = {?}$
Explanation: $ = {\dfrac{6 \times 6}{5 \times 6}} - {\dfrac{7 \times 5}{6 \times 5}} $ $ = {\dfrac{36}{30}} - {\dfrac{35}{30}} $ $ = \dfrac{{36} - {35}}{30} $ $ = \dfrac{1}{30}$